Dupixent Gains FDA Approval for Chronic Spontaneous Urticaria, Expanding Its Leadership in Autoimmune Therapeutics

On April 18, Sanofi and Regeneron jointly announced that the FDA had officially approved the supplemental Biologics License Application (sBLA) for Dupixent (dupilumab) for the treatment of Chronic Spontaneous Urticaria (CSU). This medication is the first targeted biologic therapy for CSU approved in the U.S. in a decade and represents the seventh indication for Dupixent.

Since its approval for the first indication (atopic dermatitis) in 2017, dupilumab has been approved globally for seven indications, including asthma, prurigo nodularis, chronic spontaneous urticaria, and eosinophilic esophagitis. In 2023, global sales of dupilumab reached approximately $11.6 billion, a year-over-year increase of 33%. According to Sanofi’s 2024 financial report, dupilumab successfully defended its title as the "top autoimmune drug" with $14.179 billion in sales.

In addition to the approved indications, the drug has several Phase III indications under research, including allergic rhinitis, chronic pruritus of unknown origin, and bullous pemphigoid, etc.

Chronic Spontaneous Urticaria (CSU) is a chronic inflammatory skin condition partly driven by type 2 inflammatory responses, characterized by sudden and debilitating hives and persistent itching. H1 antihistamines are the standard treatment for CSU, controlling itch and urticaria symptoms by targeting H1 receptors on cells. However, many patients remain inadequately controlled on antihistamine therapy, with limited alternative treatment options available.

From a global market perspective, the market size of Chronic Spontaneous Urticaria (CSU) is continuously expanding. In 2024, the global market size of Chronic Spontaneous Urticaria reached USD 779 million and is projected to reach USD 1.541 billion by 2032, with a compound annual growth rate (CAGR) of 8.9% from 2025 to 2032.

In the United States, more than 300,000 people with CSU have not achieved adequate control through antihistamines. Prior to the approval of dupilumab, omalizumab was the only biologic available in the U.S. for the treatment of CSU, with Novartis having dominated the field for many years through omalizumab.

The approval process for Dupilumab was not smooth. In 2023, the U.S. FDA rejected the approval of Dupilumab for the treatment of CSU due to insufficient data, requesting the company to provide more research data. Eighteen months later, the sponsor provided longer follow-up data from two Phase III clinical trials, convincing the FDA. On April 18, 2025, Sanofi announced that the FDA had approved Dupilumab for the treatment of chronic spontaneous urticaria (CSU) in adults and adolescents aged 12 years and older who still have symptoms after H1 antihistamine treatment.

This approval is based on data from two Phase III clinical studies (Study A [136 cases] and Study C [148 cases]), which involved patients aged 12 years and older who were unresponsive to antihistamine treatment and had not received biologic therapy. The studies evaluated the efficacy of adding Dupixent to standard-of-care antihistamines compared to antihistamines alone.

Both studies met the primary and key secondary endpoints: At 24 weeks of treatment, the Dupixent group showed significant improvement in itch severity and urticaria activity (a composite measure of itch and hives) compared to the placebo group, with a higher probability of achieving good disease control or complete remission. Study B (108 patients) provided additional safety data, evaluating the efficacy of Dupixent in patients who had an inadequate response or intolerance to anti-IgE therapy and were unresponsive to antihistamine treatment. The safety outcomes of the three studies were generally consistent with the known safety profile of Dupixent for its approved indications. Pooled data showed that the most common adverse reactions (≥2%) reported more frequently in the Dupixent group than in the placebo group were injection site reactions.

Dupilumab (brand name: Dupixent) is a humanized monoclonal antibody targeting IL-4Rα, jointly developed by Sanofi and Regeneron. By specifically binding to the IL-4Rα subunit shared by the interleukin-4 (IL-4) and interleukin-13 (IL-13) receptor complexes, it inhibits the signaling of IL-4 and IL-13, thereby suppressing type 2 inflammatory responses.

IL-4 and IL-13 Mediated Inflammation is a Key Component in the Pathogenesis of Asthma, Atopic Dermatitis, Chronic Rhinosinusitis with Nasal Polyps, Eosinophilic Esophagitis, and Prurigo Nodularis. The inflammation involves various cell types that express IL-4Rα (such as mast cells, eosinophils, macrophages, lymphocytes, epithelial cells, goblet cells) and inflammatory mediators (such as histamine, eicosanoids, leukotrienes, cytokines, chemokines).

By blocking IL-4Rα with dupilumab, it can inhibit inflammatory responses induced by IL-4 and IL-13 cytokines, including the release of pro-inflammatory cytokines, chemokines, nitric oxide, and IgE. Therefore, dupilumab has a very broad application space in inflammatory diseases.

In March 2017, Dupilumab was approved by the U.S. FDA for the treatment of atopic dermatitis. In its first year on the market, Dupilumab's sales were only 200 million euros. Within just two years, sales increased tenfold, rapidly surging to 2.1 billion euros in 2019. In 2023, global sales of Dupilumab reached approximately $11.6 billion, a year-on-year increase of 33%. In 2024, Dupilumab's sales further rose to $14.179 billion, surpassing AbbVie's Adalimumab and Johnson & Johnson's Ustekinumab. In just eight years, it dethroned the former "blockbuster drug" Adalimumab, successfully defending its title as the "king of autoimmune drugs."

Dupilumab Achieves Excellent Sales Performance in the Chinese Market. It was first approved for marketing in China in June 2020, successfully included in the national medical insurance in December 2020, and subsequently received approval for multiple indications. According to the sales database of Mosun Healthcare - Nationwide Hospitals (All Terminals), the in-hospital sales of Dupilumab have rapidly increased since its launch, reaching 1.422 billion yuan in 2023, with a year-on-year increase of over 50%. The overall sales are expected to be around 2.8 billion yuan. In 2024, it is projected to reach new highs, with expected sales of 3.6 billion yuan.

The huge market space has also attracted many pharmaceutical companies to lay out. Currently, in China, companies such as Hengrui Medicine, Huadong Medicine, Conmen Biotech, ZRX Biotech, CSPC Pharmaceutical Group, Akeso Biopharma, 3SBio, Connect Biopharma, Magi Biotech, Simcere Pharmaceutical, and Quanxin Biotech are among the dozens of pharmaceutical enterprises that have laid out in the IL-4Rα field.

Among them, Connect Biopharma's Spesolimab is the most advanced. On September 12, Connect Biopharma announced that its self-developed Class 1 new drug, Kangyueda (Spesolimab Injection), was approved for marketing by the National Medical Products Administration (NMPA) for the treatment of adult patients with moderate to severe atopic dermatitis. This is the first IL-4Rα antibody drug in China and the second globally to be submitted and approved for marketing, filling the gap in the field of biologics for atopic dermatitis produced in China.

In addition, several domestically produced IL-4R monoclonal antibodies have entered Phase III clinical trials, including Connect Biopharma's Ledejibart Monoclonal Antibody, Quanxin Biotech's QX005N, Zhi Xiang Jin Tai's GR1802, 3SBio's SSGJ-611, Akeso's Mandoki Monoclonal Antibody, and Hengrui Medicine's SHR-1819, among other products.

Next, several IL-4R monoclonal antibodies will be densely launched in China, and Dupixent (dupilumab), the "blockbuster drug" for autoimmune diseases, will also face a new round of challenges.